Rear visibility cameras will be required in all vehicles by May 2018, according to the US Department of Transportation National Highway Traffic Safety Administration (NHTSA), a ruling that was delayed on numerous occasions.

The agency reported that 73 percent of the vehicles that will be released by 2018 will already have the cameras anyway - but wants to ensure manufacturers will continue to provide the security either way.

"Rear visibility requirements will save lives, and will save many families from the heartache suffered after these tragic incidents occur," said David Friedman, NHTSA Acting Administrator, in a press statement. "We're already recommending this kind of life-saving technology through our NCAP program and encouraging consumers to consider it when buying cars today."

Motorcycles and trailers are exempt, but the new rule does apply to buses and trucks, as long as they weigh less than 10,000 pounds.

There are 210 fatalities and 15,000 injuries each year because of backover crashes, according to the NHTSA, with children under 5 and elderly adults above the age of 70 amounting for more than half of yearly fatalities.